Bigmind Logo Loading
GST Filing Guide

GST Return Filing Guide: GSTR-1, GSTR-3B & Annual Returns

By BigMind Advisory Team · · 8 min read

Every GST-registered business must file GSTR-1 (outward supplies) and GSTR-3B (tax summary and payment) monthly or quarterly, and GSTR-9 (annual return) if turnover exceeds ₹2 crore. Timely and accurate filing is essential to avoid late fees (₹50/day), interest (18% p.a.), and to ensure your buyers can claim input tax credit on purchases from you. BigMind Consulting manages monthly GST return filing and reconciliation for businesses in India and India.

GST return types and due dates

FormDescriptionDue DateWho Files
GSTR-1Statement of outward supplies (sales invoices and debit/credit notes)Monthly (11th of next month) or Quarterly for QRMP filers (13th of month following quarter)All regular GST-registered taxpayers
GSTR-3BMonthly summary return showing output tax, ITC claimed, and net GST payableMonthly (20th of next month). QRMP filers pay tax via PMT-06 quarterlyAll regular GST-registered taxpayers
GSTR-9Annual return consolidating all monthly returns for the financial yearAnnually (31 December for the preceding FY)Taxpayers with aggregate turnover >₹2 crore
GSTR-9CReconciliation statement comparing GSTR-9 data with audited financial statementsAnnually (31 December — filed alongside GSTR-9)Taxpayers with aggregate turnover >₹5 crore
CMP-08Quarterly self-assessment return for composition scheme taxpayersQuarterly (18th of month following quarter)Composition scheme taxpayers
GSTR-4Annual return for composition scheme taxpayersAnnually (30 April for the preceding FY)Composition scheme taxpayers

GSTR-1 — Statement of Outward Supplies

Lists all B2B invoices, B2C consolidated sales, export invoices, credit/debit notes, and advance receipts
B2B invoices reported in GSTR-1 appear in the buyer's GSTR-2B (auto-populated ITC statement)
Quarterly filers use IFF (Invoice Furnishing Facility) to upload B2B invoices for months 1 and 2 of the quarter
Errors in GSTR-1 can prevent buyers from claiming ITC — always verify invoice data before filing

GSTR-3B — Monthly Summary Return & Tax Payment

Summarises total output tax liability from all supplies made during the month
Declares input tax credit (ITC) available from inward supplies (purchases)
Net tax (output tax minus ITC) is paid through the Electronic Cash Ledger
Must reconcile with GSTR-1 and GSTR-2B — discrepancies trigger GST department notices
ITC can only be claimed if the invoice appears in GSTR-2B and the supplier has filed GSTR-1

Input Tax Credit (ITC) Reconciliation

ITC reconciliation — matching your purchase records with GSTR-2B — is critical for every GST-registered business. Unclaimed ITC is lost money; overclaimed ITC triggers tax demands and penalties.

1

Download GSTR-2B

Auto-generated monthly ITC statement showing ITC available from suppliers who filed GSTR-1

2

Match with Purchase Register

Reconcile every invoice in GSTR-2B against your internal purchase records and GST-paid invoices

3

Follow up on Missing ITC

Contact suppliers who have not filed GSTR-1 — their unfiled invoices will not appear in your GSTR-2B

Late fees and penalties for non-filing

ScenarioLate FeeInterest
Regular return (GSTR-1 / GSTR-3B)₹50/day (max ₹10,000)18% p.a. on unpaid tax
Nil return (no supplies in period)₹20/day (max ₹10,000)N/A (no tax due)
GSTR-9 (Annual Return)₹200/day (₹100 CGST + ₹100 SGST), max 0.25% of turnoverN/A

Frequently Asked Questions

What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 is a statement of outward supplies (sales invoices) that you have issued during the month or quarter. GSTR-3B is a summary return that shows your total GST liability (output tax), input tax credit (ITC) claimed, and the net tax payable for the period. Both must be filed separately and on time.

Can I claim input tax credit (ITC) on purchases if my supplier has not filed their GSTR-1?

No. Your ITC entitlement depends on the supplier's GSTR-1 being filed and the invoices appearing in your GSTR-2B (auto-populated ITC statement). If a supplier does not file their GSTR-1, you cannot claim ITC on that invoice, even if you have the physical bill and have paid GST to them.

What is the late fee for not filing GST returns on time?

For GSTR-3B and GSTR-1: ₹50 per day (₹25 CGST + ₹25 SGST) for regular returns, or ₹20 per day (₹10 CGST + ₹10 SGST) for nil returns. The maximum late fee is capped at ₹10,000 per return (₹5,000 CGST + ₹5,000 SGST). Interest at 18% per annum applies on unpaid tax.

Is GSTR-9 (Annual Return) mandatory for all GST-registered businesses?

GSTR-9 is mandatory for taxpayers with aggregate annual turnover exceeding ₹2 crore in a financial year. Businesses with turnover up to ₹2 crore are exempt from GSTR-9 filing. GSTR-9C (reconciliation statement and audit) is mandatory for businesses with turnover above ₹5 crore.

What is the composition scheme and how does it affect GST return filing?

Businesses with turnover up to ₹1.5 crore (₹75 lakh for service providers) can opt for the composition scheme and pay GST at a flat reduced rate. Composition dealers file CMP-08 (quarterly) and GSTR-4 (annual return) instead of GSTR-1 and GSTR-3B. They cannot issue tax invoices or claim input tax credit.

Need help with GST return filing?

BigMind Consulting handles monthly GSTR-1, GSTR-3B, and annual GSTR-9 filing for businesses across India. Book a free consultation.

BigMind Consulting · GST Filing & Compliance · India